Flexible dummy bar for continuous casting machines



H. LEMPER 3,442,322

FLEXIBLE DUMMY BAR FOR CONTINUOUS CASTING MACHINES May 6, 1969 FiledSept. 9, 1966 Q w WM MN United States Patent U.S. Cl. 164-274 8 ClaimsABSTRACT OF THE DISCLOSURE I disclose a flexible dummy bar forcontinuous casting machines, said dummy bar comprising an elongatedflexible band member, a plurality of gauge blocks loosely mounted onsaid band member, said gauge blocks each being of a thickness equal tothat of a continuous body to be cast, said gauge blocks being disposedin a tandem array along the length of said band member and beingrelatively closely spaced with clearances such as to permit flexure ofsaid band member when said dummy bar is passed through said castingmachine, at least some of said gauge blocks being shaped so as tostraddle portions of said gauge blocks in a direction longitudinal ofsaid band in order to present a substantially and continuously smoothsurface to said casting machine.

The present invention relates to starting bars for continuous castingmachines and more particularly to a flexible starting bar which can beutilized with equal facility in starting the strands or continuousbodies to be cast in continuous casting machines wherein the strands arebent through arcuate paths from vertical positions to horizontalpositions, and in continuous casting machines wherein the strands beingcast are not bent at all.

The advantages of utilizing flexible starting or dummy bars rather thansolid bars of soft metal to start the strands of continuous castingmachines, have long been appreciated in the continuous casting art.Flexible starting bars have been proposed heretofore for continuouscasting machines, for example, the chain type and/ or the segmentedtype. Known flexible starting bars have, however, been heavy complexunits that are very expensive to manufacture and to maintain.Additionally, their weight alone has made them extremely cumbersome anddiflicult to handle. Prior flexible starting bars have utilized arelatively large number of component parts which not only add to theirWeight but greatly increase the likelihood of expensive breakdownsduring use resulting in wasted strands and loss of production time.

I overcome these difliculties of the prior art by providing a novel,flexible dummy bar that is much lighter, simplier and less expensive tomanufacture, simplier to repair, and easier to handle than flexiblestarting bars heretofore known. Moreover, the flexible dummy bar of thepresent invention is fabricated from relatively few component parts andis arranged for quickly attaching and detaching the dummy bar relativeto the ends of the continuous strands.

I provide a flexible dummy bar comprising an elongated flexible bandmember having a plurality of gauge block elements loosely mountedthereon such that the proponderant proportion of at least one side ofthe flexible band is covered by the gauge blocks, said gauge blocksdesirably being shaped to cover substantially the entire surface of bothsides of the flexible band while permitting the bar to flex about agiven radius in the case of vertical casting machines, said gauge blocksbeing relatively closely spaced from one another and arranged on theflexible band such that a constant thickness of the length 3,442,322Patented May 6, 1969 of the dummy bar is presented to pinch rollsdisposed thereacross along the path thereof when passing through saidcontinuous casting machine. In other arrangements the dummy bar isprovided with head means for engaging .the molten material strand as itis initially formed in the mold structure of the continuous castingmachine, and with tail piece means for engagement by suitable tractionor. withdrawal apparatus for drawing the dummy bar through said pinchrolls.

In still other arrangements of the invention I provide detachable dummybar head means which are secured to the metal strand by embedding withinthe molten material thereof and held therein when the materialsolidifies. The gauge blocks of the dummy bar can be closely spaced sothat the clearances therebetween are largely eliminated when the dummybar is bent around its intended radius of curvature, in vertical castingmachines. Desirably, I provide a flexible dummy bar which can besubstantially square in cross sectional configuration so that the dummybar can be used for both billet and slab sized strands. It will beunderstood, of course, that a rec tangular cross sectional configurationcan be imparted to the flexible dummy bar pursuant to the teachings ofthe present invention. The latter arrangement is desirable for use withcontinuous casting machines which are used only to cast slabs of thesame width. Then, desirably, the flexible dummy bar is of the same crosssectional configuration as that of the slabs.

Preferably each of the gauge blocks comprises a pair of similarly shapedelements rigidly fastened to a spacer member, with the spacer beingthicker than the flexible band member and loosely mounted in an openingtherein so that the gauge blocks are loosely mounted on the flexibleband member to obviate interference with the flexure thereof.

I also desirably provide gauge blocks of differing contours and arrangedsuch that the gauge blocks of one con tour alternate with those ofanother contour to provide a longitudinally overlapping and closelyspaced array of gauge blocks along the length of the flexible bar. Inone arrangement of this latter feature of the invention the gauge blocksare arranged in tandem array along the length of the flexible bar.Desirably, also, the aforementioned head and tail means are of similarcross sectional configuration relative to the gauge blocks, so that theyare, in effect, continuations of the flexible portion of the dummy bar.

During the foregoing description various objects, features andadvantages of the invention have been alluded to. These and otherobjects, features and advantages of the invention 'will be elaboratedupon during the following description of presently preferred embodimentsof the invention together with presently preferred methods of practicingthe same.

In the accompanying drawings, I have shown certain presently preferredembodiments of the invention and have illustrated certain presentlypreferred methods of practicing the same wherein:

FIGURE 1 is a side elevational view of the flexible dummy bar of theinvention as used in a vertical continuous casting machine;

FIGURE 2 is an enlarged top plan view of the flexible dummy bar shown inFIGURE 1 but shown here in its unflexed condition;

FIGURE 3 is a side elevational view of the flexible dummy bar as shownin FIGURE 2; and

FIGURE 4 is a cross sectional view of the flexible dummy bar as shown inFIGURE 3 and taken along reference line IVIV thereof.

Referring now more particularly to the drawings and initially to FIGURE1, flexible dummy bar 10 is illustrated in connection with a verticalcontinuous casting machine exemplified schematically by mold structure12 and 'withdrawal apparatus of which the guide and pinch rolls 14 and16 form a part. As better shown in FIGURES 2 and 3 of the drawings, theflexible dummy bar includes a flexible band 18 having a plurality ofopenings 20 therein which in this example are equally and tandemlyspaced along the length of the band 18. Preferably, the flexible dummybar 10 which includes head connector 22 and tail connector 24 is as longas the distance of the path of travel of the strand to be cast from themold 12.to the cut-off station (not shown) of the continuous castingmachine, but is at least as long as the distance from the mold structure12 to the first pair of pinch rolls 16 of the aforementioned withdrawalequipment.

A gauge block 26 or 28 is mounted on the flexible band 18 of each of itsopenings 20, with the result that the blocks 26, 28 are aranged in atandem array. Desirably the gauge blocks 26 and 28 each extendsubstantially across the width of the band 18, and are of H and roundconfigurations, respectively. The gauge blocks 26, 28 are alternatedalong the length of the flexible bar 18 so as to provide an interfittingor overlapping array of the gauge blocks. That is to say, thelongitudinally extending arms 30 of the gauge blocks 26 overlap theadjacent extremities 32 of the gauge blocks 28 in a directionlongitudinal of the flexible band 18. This overlapping arrangementprevents the ends or extremities of the individual gauge blocks frombeing damaged by the pinch rolls 16 as the dummy bar is drawntherethrough. Other configurations of one or both groups of blocks 26,28 can obviously be utilized, within the teachings of the presentinvention.

With reference now to FIGURES 2 and 4 of the drawings, it will be seenthat each of the gauge blocks is formed from a complementary pair ofgauge block elements 26a, 26b or 28a, 28b. Each such pair of gauge blockelements are secured rigidly to opposite sides of an annular spacer 34,which desirably is thicker than the flexible band 18.'The outer diametermoreover of the annular spacer 34 is less than the diameter of the bandopenings 20 so that the complementary elements 26a, 26b and 28a, 28b arespaced from the adjacent surfaces of the band 18 in order to provide thenecessary clearances for flexure of the band 18. Each of the gauge blockelements is provided with a central aperture alignable with the centralaperture of its associated spacer 34, and the component parts of eachgauge block are rigidly secured by means of a rivet 36.

When thus assembled on the flexible band 18 the gauge blocks 26 and 28are each loosely and pivotally mounted thereon. However, the pivotalmovement of the gauge blocks 26 is limited by clearances 38 between theouter end portions of the arms 30 and the adjacent outer periphery ofthe gauge blocks 28. The lateral surfaces 40 of the arms 30 as viewed inFIGURE 2 of the drawings are inclined inwardly to an extent sufficientto prevent the arms 30 from overhanging the lateral edges of the band 18when the gauge blocks 26 are thus pivoted. This pivotal movement of thegauge block 26 is desirable to ensure that the clearances 38 are equalwhen required, to permit proper flexing of the metal band 18.

At its ends, the flexible band 18 terminates in laterally extendingbearing members 42 which are loosely fitted into complementary recesses44 respectively formed in the tail connector 24 and in link member 46forming part of the head connector 22. The relatively loose fittingofjoint 50 so that the remainder of the dummy bar '10 can be quicklyremoved from the strand and after the latter passes through the pinchrolls 16 and other portions of the withdrawal equipment. In thisarrangement the quick-detach joint includes a transverse cylindricalbore 52 formed transversely through the longitudinally extending arms 54of the link member 46 and a retaining pin 56 secured thereto and havingan intermediate flattened portion 58. By moving the detachable headpiece 48 of the head connector 22 to a position substantially at rightangles to that shown in FIGURE 3 of the drawings the headpiece 48 can beremoved from the link member 46 by passing the flattened portions 58 ofthe pin 56 through a complementary restricted access opening portion 60of head piece 48. In furtherance of this purpose the inward end-ofthehead piece 48 is rounded as denoted by reference character 62 and theintermediate shouldered portions of the head piece portion are roundedin concave fashion at 64 to permit the aforementioned angulardisposition of the head piece 48.

Desirably, the head connector 22 is provided with suitable keying meanssuch as bolt 66 which is threaded into a longitudinally tapped apertureof the head piece 48 in order to ensure retention of the head piece 48in the adjacent end' of the strand when the latter solidifies. Athreaded shaft 68 or the like shown in fragmentary form in FIGURE 3 andforming part of the aforementioned withdrawal equipment,- can besimilarly secured to the tail connector 24.

The adjacent or inward end portions of the tail connec: tor 24 and ofthelink member 46 are rounded at 70 and 72 respectively for interfittingassociation with the endmost gauge blocks 26a and 2617 respectively.

Although the flexible dummy bar 10 has been illustrated as square incross sectional 'configuration, it will be understood-that the" gaugeblocks 28 can be formed with elements of larger diameter andthat theelements of the gauge block 26 can be formed with correspondingly largerplan areas in order to impart a rectangular configuration to theflexible dummy bar 10. At the same time the width of'the flexible band18 can be increased to the extent that the diameter of the gauge block28 is increased. It will'als o be understood that the thickness of thegauge blocks 26 and 28 can be made correspondingly greater'or lesser toconform the flexible dummy bar 10 to a given thickness of the caststrand with which it is associated; Thus, the gauge blocks 26, 28 are ofthe same thickness as the strands to be cast, and preferably the widthsof the flexible band 18 and of the gauge blocks 26;"28 are'the same asthat "of the strands so that the strands are started throughthe castingmachine in perfecfaligninent. It should be noted that although the gaugeblocks 26,28 are loosely'mount'ed on the flexible band'18, theycontinuously present a smooth surface of i constant thickness to thepinch rolls 16.

' From the foregoing it will be apparent that novel and eflicient formsof flexible dummy bars have been disclosed herein. The flexible dummybar of the invention is lighter-and morexsimply constructed than knowntypes and therefore is easier to'manipulate and lessexpensive tofabricate and maintain. Atthe sametime, having relatively few componentparts, git'is of a rugged structural design.,Wh;ile Lhave-shoWn certainpresently preferred embodiments of theinventionandhave described certainof a thickness equal tothat ofv a continuous body'to becastfseiid"gaugeblocks being disposed. in a tandem array along thelength of saidband member and being relatively closely spaced withclearances such as to permit flexure of said band member when said dummybar is pressed through said casting machine, some of said gauge blocksbeing shaped so as to straddle portions of adjacent gauge blocks in adirection longitudinal of said band in order to present a substantiallyand continuously smooth surface to said casting machine.

2. The combination according to claim 1 wherein said some gauge blocksare pivotally mounted on said band member so that uniform clearancesbetween said gauge blocks are maintained during fiexure of said bandmembet.

3. The combination according to claim 1 wherein said some gauge blocksand the remainder of said gauge blocks are disposed in an alternatingarray along the length of said band member.

4. A flexible dummy bar for continuous casting machines, said dummy barcomprising an elongated flexible band member, a plurality of gaugeblocks loosely mounted on said band member, said gauge blocks each beingof a thickness equal to that of a continuous body to be cast, said gaugeblocks being disposed in a tandem array along the length of said bandmember and being relatively closely spaced with clearances such as topermit flexure of said band member when said dummy bar is passed throughsaid casting machine, some of said gauge blocks being shaped so as tooverlap portions of adjacent gauge blocks in a direction longitudinal ofsaid band in order to present a substatially and a continuously smoothsurface to said casting machine, said some gauge blocks and theremainder of said gauge blocks being disposed in an alternating arrayalong the length of said band member, said remaining gauge blocks beingof generally circular configuration having a diameter substantiallyequal to the width of the band member, and said some gauge blocks havinglongitudinally'extending arm portions disposed to protrudelongitudinally beyond the nearest portions of said remaining gaugeblocks.

5. The combination according to claim 4 wherein said some gauge blocksare pivotally mounted on said band member for limited pivotal movementdefined by clear ances between said arm portions and the periphery ofadjacent ones of said remaining gauge blocks.

6. The combination according to claim 5 wherein said some gauge blockshave a width substantially equal to that of said band member and theouter surfaces of said arm portions are tapered inwardly to obviatetheir overhanging the adjacent lateral edges of said band member duringsaid limited pivotal movement.

7. The combination according to claim 1 wherein the ends of said bandmembers are loosely secured in head and tail connector respectively, andthe inward ends of said head and tail connectors are shaped foroverlapping disposition relative to the adjacent endmost ones respec'tively of said gauge blocks.

8. The combination according to claim 1 wherein the ends of said bandmember are secured in head and tail connectors respectively, thetransverse sectional config uration of said head and tail connectorsbeng substantially similar to adjacent ones of said gauge block's.

References Cited UNITED STATES PATENTS 2,920,359 1/ 1960 Easton et al164269 3,262,162 7/1966 Lemper 164274 3,324,934 6/1967 Hess et a1164-274 3,351,125 11/1967 Colombo 164 -274 FOREIGN PATENTS 1,421,502 11/1965 France.

J. SPENCER OVERHOLSER, Primary Examiner. R. S. ANNEAR, AssistantExaminer.

US. DEPARTMENT OF COMMERCE PATENT OFFICE Washington, D.C. 20231 UNITEDSTATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,442,322 May6, 1969 Herbert Lemper It is certified that error appears in the aboveidentified patent and that said Letters Patent are hereby corrected asshown below:

Column 1, line 24 "said", first occurrence, should read adjacent line64, "proponderant should read preponderant Column 3 line 18, aranged"should read arranged Column 5, line 2, "pressed" should read passed line27, "substatially should read substantially Columr 6, line 14,"connector should read connectors line 21, "beng" should read beingSigned and sealed this 14th day of April 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Commissioner of Patents Edward M. Fletcher, J r.

Attesting Officer

